A hot potato: Elon Musk has never been shy when it comes to criticizing the Covid-19 lockdowns and downplaying the seriousness of the coronavirus. Now, the Tesla boss is questioning whether tests that detect the virus are accurate after he took four in one day, two of which came back positive while two were negative.

In a recent tweet, Musk wrote: "Something extremely bogus is going on. Was tested for covid four times today. Two tests came back negative, two came back positive. Same machine, same test, same nurse. Rapid antigen test from BD." He is likely referring to Becton Dickinson and Co's rapid antigen test. "If it's happening to me, it's happening to others," he warned.

In replies to other Twitter users, Musk said he was showing symptoms of a "typical cold." The CEO is also getting PCR (polymerase chain reaction) tests from separate labs, with results expected back in 24 hours.

As noted by Reuters, antigen test supplier Becton Dickinson said in September that it was investigating reports from nursing homes that its rapid coronavirus testing equipment was producing false-positive results. The US Food and Drug Administration has warned that Covid-19 antigen tests can show false positives.

In April, Musk said coronavirus shelter-in-place orders were "fascist" and infringed on people's rights. He had previously claimed there would be "close to zero new cases" of Covid-19 in the US by the end of April. His views incurred the wrath of fellow billionaire Bill Gates, who called Musk's comments "outrageous."

During an interview on the podcast "Sway" in September, Musk said neither he nor his family would be getting a Covid-19 vaccine because he was "not at risk for Covid, nor are my kids."

The latest Coronavirus statistics for the US show that 10,873,936 people in total have tested positive for the virus, and there have been 248,585 deaths, more than any other country.